Controlled Synthesis of High-index Faceted Pt nanocatalysts Directly on Carbon Paper for Methanol Electrooxidation

Platinum (Pt) nanocatalysts as the best catalysts for direct methanol fuel cell (DMFC) still face a huge challenge such as high cost, low utilization rate, activity and stability to be improved. Adjusting the surface structure of Pt nanoparticles (NPs) to achieve high-index facets with more active sites is an effective method to resolve the problems. Furthermore, the controlled synthesis of high-index faceted Pt (HIF-Pt) nanocatalysts directly on carbon paper, which is an important component of membrane electrode, can greatly promote the practical application of HIF-Pt nanocatalysts in DMFC. Herein, the HIF-Pt nanocatalysts supported on carbon paper (HIF-Pt/CP) were realized by developing an electrochemically controlled synthesis method. The fishbone-like and concave cube shaped Pt NPs surrounded by some high-index facets such as (200), (220), and (311), were achieved by adjusting the frequency and treatment time of applied potential. Hence, these HIF-Pt/CPs exhibit excellent activity and stability towards methanol electrooxidation during both cyclic voltammetry characterization and potentiostatic test. Especially, the specific activities and mass activities of HIF-Pt/CP-1 Hz reached 3.78 mA·cm −2 and 1.53 A·mg −1 , which were 6.5 and 2.78 times higher than those of commercial Pt/C, respectively. And the direct growth of HIF-Pt NPs on carbon paper effectively improves the stability of the catalyst layer which shows great potential in the practical application in DMFC. Graphical Abstract